Converter.



I H. SHOEMAKER.

' CONVERTER.

APPLICATION FILED DEC. 20, 1906. 899,629, Patented Sept.29,1908.

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CONVERTER.

APPLICATION FILED DEGHZO, 1908. 8995629 Patented Sept. 29, 1908.

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flthnnu Q/witnesses ewmzwez;% am) 8. er My UNITED sTAfMENT ontoHARRYSHOEMAKER, OFJERSEY CITY, NEW JERSEY, ASSIGNOR TO INTERNATIONALTELEGRAPH CONSTRUCTION COMPANY, A CORPORATION OF NEW YORK.

CONVERTER.

Specification of Letters Patent.

7 Patented Sept. 29, 1908.

Application filed December 20, 1906. Serial No. 348,715.

To all whom it may concern:

citizen of the United States, residing at Jersey City, in the county ofHudson and State of New Jersey, have invented a new and usefulConverter, of which the following is a specification.

My invention relates to apparatus for de riving from direct orcontinuous electric current, fluctuating or alternating current.

.The apparatus comprises means in the nature of a commutator, rotated atsuitable speed, resistancesor inductances, or both, being employed tosecure rounded wave forms which are more desirable on the alternatingcurrent side and which also increase the efficiency of conversion.

The converter does not involve field magnets and is so diflerentlatedfrom rotary converters or motor generators which are dynamo electricmachines.

My invention resides also in wireless telegraph transmitting apparatusemploying sue a converter which makes it possible to do away with motorgenerator sets, rotary converters, and the like, which require so muchspace especially on shipboard or other restricted places.

My invention resides alsoin further features hereinafter described andpointed out in the claims. 7

For an illustration of a form my invention may take reference is to behad to the accompanying" drawings, in which:

Figure 1 is a diagrammatic view illustrating a converter. Fig. 2 is adiagrammatic view illustrating the converter in combination .withwireless telegraph transmitting apparatus.

Referring to Fig. 1, -1 and 2 represent slip rings uponwhich bear thebrushes 3 and 4 respectively, and which connect to the direct orcontinuous current supply. From the slip ring 1 connection is made bythe conductors 5 and 6 with the diametrically opposed commutatorsegments 7 and 8. Similarly, the slip ring 2 is connected by theconductors 9 and 10 with the diametrically opposedcommutator segments11- and 12. These commutator segments 7, 8 and 11, 12 divide thecommutator proper .into quadrants, each quadrant consisting of aplurality of narrower segments as, 13. These quadrants will, for thesake of convenience, be referred to as A, B, O, and D. The two seg- Iments next to the segment 7 are cross con- Be 1t known that I, HARRYSHOEMAKER, a I nected, and so are the successive pairs of similarly, thehalves of the quadrants A and 1 C, on either side of the segment 12, arecross connected in pairs; and likewise the halves of the quadrants ofthe segments B and D,

on either side of the segment 7, are cross connected in pairs. Similarsoi'the halves of quadrants on either side of the segment 7 are crossconnected with similars of the halves of the quadrants C and Don eitherside of the'segment 8. And similars of the halves of quadrants B and Don either side of segment 11 are cross connected with similars ofquadrants A and O on either side of segment 12.

The neighboring halves of each quadrant I are in'electricalcommunication with each other through the relatively high resistance 14through the various cross connections. From the segment 7 to the mostdistant segments of the halves of quadrants A and B on either side ofsegment 7, extends the resistance 15 (inductive or non-inductive). Thisresistance is connected at suitable points with the various crossconnections between the segments symmetrically located on either side ofthe segment 7. The amounts of resistances between the various crossconnections may be determined by calculation or experiment and are sochosen as to size of conductor and as to resistance of'the 'sections orincrements that when-the apparatus is rotated at suitable speed analternating current wave of sine form is more or less nearlyapproximated. The same resistance,

15, serves for the halves of quadrants C and D'on either side of thesegment 8 because of the cross connections. Similarly, a resistance orinductance 16 is connected in sections with the'various crossconnections of the remaining half of the commutator.

Brushes 17 and 18 are cross connected by the conductor 19 and bear upondiametrically opposite points of the commutator, the conductor 20forming one ,terminal of the alternating current side of the device.Similarly, the brushes 21 and 22 are cross connected by conductor 28 andbear upon diar nating current side;

' metrically opposite points of the commutator and on a diameter-zit riht angles with the brushes 17 and 18. Andlthe conductor '24 forms thesecondterminalbf' the alter- The commutator and slip rings and theinductances or resistances are all suitably mounted upon a shaft and r0-tated at desired s eed, the direct current being fed in at brus es 3 and4, and the alternating or fluctuating current taken off through thebrushes 17, 18 and2l, 22.

The apparatus so mounted upon a shaft, is 7 shown in Fig. 2, where ashaft is represented by 25, suitably supported in the bearings 26,

27. 'The various cross connections may be made within the commutator.And the resistances or inductances rotate with the shaft and commutatorand are suitablyinclosed within the commutator or within theextending-cylindrical portion or member 28. Or the resistances may beexternal and stationary and slip rings and brushes provided to l1l cludethemproperly in circuit. I G represents a generator of direct orcontinuous current connected to the supply conductors 29, 30. The brush3 is connected to the'conductor 29 through the variable resistance 31,the brush 4 bein connected to the conductor 30. To suitab y rotate theconverter, the direct current motor E is provided, its armature 32 beingmounted upon the shaft and its field ring 33 suitably sup rted andcarrying the field poles 34. The eld winding is connected on the onehand to conductor and on the other through the variable resistance 35 tothe conductor 29. .The armature is connected throu h conduc tor 36 withthe conductor 30 and t rough the i j rheostat or adjustable resistance37 with the conductor 29.

The conductors 20 and 24 on the alternating current side of theconverter, connect with the primary 38 of a transformer whose secondaryis 39. The interposition of the transformer serves to roduce, in itssecondary circuit,a more tru y alternating current. The secondary 39' isconnected by the conductors. 40 and 41 to two of the poles of thefour-poleswitch 43. And similarly, the direct current supply isconnected by conduc tors 44 and 45 w1th the other two poles of thefour-pole switch. This makes available then both direct and alternatingcurrent for the wireless telegraph transmitting apparatus involving asynchronously rotating spark gap, the spark gap terminals beingrepresented at 46 and 47. This spark gap and its associated drivingmechanism 'and circuits are similar to the apparatus shown and describedin my copending application Serial No. 347,950. I The 's ark gapterminal 46 is rotated by the sha t 48 upon which are mounted thearmatures 49 and 50 of the synchronous alternating current motor M anddirect current 'for control purposes.

motor'N. The field winding 51 ofthe alternating current motor M isenergized by direct current' derived from the conductors 52 and 53, anadjustable resistance, 54 intervening And'the winding of thearmature 49receives alternatin current through conductors 55 and 56, the adjustableresistance 57 intervening. The armature of the directcurrent motor Nreceives its current from the conductors 52 and 53 through the rheostator adjustable resistance 58. And the field windings 59 receive currentfrom the same conductors, an adjustable "resistance 60 being provided insuch field circuit.

With the motor E brou ht u to and maintained at suitable speed, t e teegraph opera-- tor closes the four-pole switch 43 and by means of therheostat 58 brings the direct current motor N up to suitable speed andthe asynchronous motor M then maintains the speed precisely atsynchronism, so that the spark gap terminals are rotated with respect toeachother at synchronous speed. By adj ustin the field or armaturerheostats of the several motors, all desired control may be exercised,and by controlling the speed of the motor E, the frequency of thealternating current supply is determined, such motor being controlled byits armature andl field rheostats in the well. known man'- ner. Totransmit messages, after the apparatus is thus in motion, the o eratormanipulates his key 61 which then allows alternating currentfromconductors 62 and 63 to pass through the primary P of the transmittingtransformer whose secondary is represented.

at S. A variable resistance or inductance 64 serves to properly controlthe current in the primary circuit. Bridged across the ter- 'minals ofthe secondary S, are the two condensers K, K which are included inseries with the circuit of the spark gap 46, 47 and the mductance 65, avariable portion of which is included in this circuit and anothervariable portion of which is included between the aerial radiatingconductor 66 and the earth 67.

By the herein described apparatus, alternating current may beefliciently derived from a direct current source without recourse 'tomotor generators or rotary converters or other dynamo-electricmachinery, which not only require much more space than the appa ratusherein described but are also ineflicient.

render the conversion'more efficient than in 13f) sea-s29 means of thedriving mechanism, the. frequency may be made anything desired, the [lowof current from the direct current source is controlled by theadjustable resistance 31.

Altogether the apparatus is compact and a most efficient converter fromdirect to alternating current and is particularly adaptable to signalingin wireless telegraphy especially in constricted surroundings, as onshipboard, it being remembered that the current supply on shipboard isalmost invariably direct current.

/Vhile I have herein shown and described a wireless signaling system andapparatus involving myconverter, I do not herein make claim to saidwireless signaling system and apparatus but reserve the same for anotherapplication.

VJhat I claim is:

1. The combination with a converter, of a plurality of commutatorsegments, resistances in varying amounts connected between saidcommutator segments, brushes bearing upon said segments, and means forsupplying direct current to said segments at symmetrical points.

2. A converter comprising a plurality of commutator segments,resistances in varying amounts connected between said segments, sliprings in communication with a direct current sourc and connections fromsaid slip rings to symmetrically located segments.

3. In a converter, a plurality of rotating commutator segments,resistances in varying amounts connected between said segments androtating with said segments, brushes bearing upon said se ments, slip'rings coinmunicating with a direct current supply, and connections fromsaid slip rings to said symmetrically located segments.

4. The combination with a plurality of segments, of resistances invarying amounts bearing upon said segments, means for sup- .plyingdirect current to symmetrical y said segments and. resistances atdesired speed.

5-. In combination, a converter comprising a plurality of commutatorsegments, resists ances in varying amounts connected between saidcommutator segmcnts, brushes bearing upon said segments, means forsupplying direct current to said segments at symmetrical points, meansfor rotating said commutator, a direct current motor connected with adirect current supply, and an alternating current synchronizing motorassociated with said, direct current motor and deriving alternatingcurrent from said converter.

In testimony whereof I have hereunto affixed my signature in thepresence of the two subscribing witnesses.

HARRY SHOEMAKER.

Witnesses DUFFY, A. D. KNEUPER.

connected between said segments, brushes located segments, and means forrotating

